1. Field of the Invention
The present invention relates to a method of installing a floating marine platform. More particularly, the present invention relates to a marine platform and a method of installing a marine platform using multiple buoys that support a platform and wherein tensile anchor cables connect to a deck part of the platform at the center of the deck. In one embodiment, an improved buoy construction is provided with longitudinal, transverse and diagonal members (e.g., welded) and having a lower ballast section, upper buoyant section and intermediate neutral buoyancy section.
2. General Background of the Invention
Many types of marine platforms have been designed, patented, and/or used commercially. Marine platforms typically take the form of either fixed platforms that include a large underwater support structure or “jacket” or a floating platform having a submersible support. Sometimes these platforms are called semi-submersible rigs.
Jack-up barges are another type of platform that can be used in an offshore marine environment for drilling/production. Jack-up barges have a barge with long legs that can be powered up for travel and powered down to elevate the barge above the water.
Other types of platforms for deep water (for example, 1500 feet (457.2 meters) or deeper) have been patented such as spars and others. Some of the following patents relate to offshore platforms, some of which are buoy type offshore platforms, all of which are hereby incorporated herein by reference. Other patents have issued that relate in general to floating structures, and including some patents disclosing structures that would not be suitable for use in oil and gas well drilling and/or production. The following Table lists examples of marine platforms. The order of listing is numerical, and is otherwise of no significance.
TABLEISSUE DATEPATENT #DD/MM/YYYYTITLE2,952,23413-09-1960Sectional Floating Marine Platform3,540,39617-11-1970Offshore Well Apparatus and System3,982,49228-09-1976Floating Structure4,286,53801-09-1981Multipurpose Floating Structure4,297,96503-11-1981Tension Leg Structure for Tension Leg Platform4,620,82004-11-1986Tension Leg Platform Anchoring Method and Apparatus4,714,38222-12-1987Method and Apparatus for the Offshore Installation of Multi-ton Prefabricated Deck Packages on Partially Submerged Offshore Jacket Foundations5,197,82530-03-1993Tendon for Anchoring a Semisubmersible Platform5,423,63213-06-1995Compliant Platform With Slide Connection Docking to Auxiliary Vessel5,439,06008-08-1995Tensioned Riser Deepwater Tower5,558,46724-09-1996Deep Water offshore Apparatus5,607,26004-03-1997Method and Apparatus for the Offshore Installation of Multi-ton Prefabricated Deck Packages on Partially Submerged Offshore Jacket Foundations5,609,44111-03-1997Method and Apparatus for the Offshore Installation of Multi-ton Prefabricated Deck Packages on Partially Submerged Offshore Jacket Foundations5,662,43402-09-1997Method and Apparatus for the Offshore Installation of Multi-ton Prefabricated Deck Packages on Partially Submerged Offshore Jacket Foundations5,706,89713-01-1998Drilling, Production, Test, and Oil Storage Caisson5,722,79703-03-1998Floating Caisson for Offshore Production and Drilling5,799,60301-09-1998Shock-Absorbing System for Floating Platform5,800,09301-09-1998Method and Apparatus for the Offshore Installation of Multi-ton Packages Such as Deck Packages, Jackets, and Sunken Vessels5,873,41623-02-1999Drilling, Production, Test, and Oil Storage Caisson5,931,60203-08-1999Device for Oil Production at Great Depths at Sea5,924,82220-07-1999Method for Deck Installation on an Offshore Substructure5,975,80702-11-1999Method and Apparatus for the Offshore Installation of Multi-ton Packages Such as Deck Packages and Jackets6,012,87311-01-2000Buoyant Leg Platform With Retractable Gravity Baseand Method of Anchoring and Relocating the Same6,027,28622-02-2000Offshore Spar Production System and Method forCreating a Controlled Tilt of the Caisson Axis6,039,50621-03-2000Method and Apparatus for the Offshore Installation of Multi-ton Packages Such as Deck Packages and Jackets6,149,35021-11-2000Method and Apparatus for the Offshore Installation of Multi-ton Packages Such as Deck Packages and Jackets6,318,93120-11-2001Method and Apparatus for the Offshore Installation of Multi-ton Packages Such as Deck Packages and Jackets6,364,57402-04-2002Method and Apparatus for the Offshore Installation of Multi-ton Packages Such as Deck Packages and Jackets6,367,39909-04-2002Method and Apparatus for Modifying New or Existing Marine Platforms6,435,77320-08-2002Articulated Multiple Buoy Marine Platform Apparatus and Method of Installation6,435,77420-08-2002Articulated Multiple Buoy Marine Platform Apparatus6,692,19017-02-2004Articulated Multiple Buoy Marine Platform Apparatus6,719,49513-04-2004Articulated Multiple Buoy Marine Platform Apparatus and Method of Installation7,527,00605-05-2009Marine Lifting ApparatusGB 2092664 18-08-1982Ball-and-Socket Coupling for Use in Anchorage of Floating Bodies
One of the problems with single floater type marine platform constructions or “spars” is that the single floater must be enormous, and thus very expensive to manufacture, transport, and install. In a marine environment, such a structure must support an oil and gas well drilling rig or production platform weighing between 500 and 40,000 tons (between 454 to 36,287 metric tons), for example (or even a package of between 5,000-100,000 tons (4,536 to 90,718 metric tons)).